Obstructive Sleep Apnea (OSA) is a major sleep disorder with a prevalence of about 15 % among US adult population and can lead to cardiovascular diseases and stroke. In this study, we have investigated the OSA-induced concurrent rise in cerebral blood flow velocity and blood pressure in 5 positively diagnosed sleep apnea subjects. The subject population had a mean AHI of 57.94±25.73 and BMI of 33.66±7.27 kg/m(2). The results of this preliminary study yielded a relatively high correlation between rise in blood pressure and rise in cerebral blood flow velocity during apnea episodes (r=0.61±0.16) compared to normal breathing (r=0.28±0.26). These findings suggest that cerebral autoregulation may be less effective during apnea episodes.